1. Field of the Invention
The invention relates to resonant power converting circuits; in particular, to a DC-DC converting circuit and a multi-phase power controller used for controlling the resonant power converting circuits.
2. Description of the Prior Art
In general, in the field of network equipment or automotive electronics, power converters are usually used to convert high voltages to low voltages. For example, FIG. 1 illustrates a schematic diagram of a conventional multi-phase resonant power converting circuit. When the output load Rload of the conventional multi-phase resonant power converting circuit fluctuates, its multi-phase power controller usually outputs a pulse width modulation signal with a fixed duty cycle to the resonant power converting circuit and changes switching frequency according to a voltage feedback signal related to the output voltage Vo to achieve the linear voltage regulation function.
However, in practical applications, when each phase resonant power converting circuit in a conventional multi-phase resonant power converting circuit has a different parasitic inductance capacitance, even at the same frequency, each phase resonant power converting circuit will have different voltage gains, resulting in a reduction of the overall system performance, and due to the lack of current balance control mechanism of the conventional multi-phase resonant power converting circuit, it is difficult to effectively improve the current efficiency in parallel connection.